I Couldn't
by Gamma Orionis
Summary: It's surprisingly easy to do things we never thought we could. AU. Written for Paris in December's Marry/Shag/Kill challenge. Bellatrix/Lily, Bellatrix/Tom Riddle
1. Marry

Written for Paris in December's Marry/Shag/Kill challenge on Megsy42's Harry Potter Fanfiction Challenges forum.

"Given three characters, you have to choose one to marry, one to shag, and one to kill. (Simple, right?) Well, in this challenge, you get a fourth character, whose job it is to do the marrying, shagging, and killing. That's the story you write!"

My chosen character: Bellatrix Black

Marry: Lily Evans

Shag: Tom Riddle

Kill: Marlene McKinnon

The first chapter's pretty fluffy, but I promise it gets darker.

)O(

Lily Evans sometimes had trouble believing how lucky she had been. Little Mudblood girl, born to a family of no importance even in the muggle world, nowhere near top of any of her classes, not particularly popular, average in every way. And she had fallen in love with the last person she ever thought would love her back.

Bellatrix Black was four years older than Lily. She was the eldest daughter of the Blacks, the most prestigious Pureblood family in England. She had been brilliant in classes, and would have gotten full marks in nearly everything if she had turned up to lessons a little more often. She didn't have many friends, but people admired her. She was what every girl in the school wanted to be.

And she had fallen for the quiet, redheaded Mudblood, four years below her.

And that was why Lily had been lucky.

Bellatrix brushed her hand over Lily's face, kissed her gently. The two girls were sitting on Lily's bed in her muggle house, the sunset throwing crimson light over the room. Bellatrix had had to sneak out of Black manor to meet her girlfriend, but, as she said, that only made it more exciting.

"You, my Lily, are beautiful," Bellatrix whispered. "Perfectly, wonderfully beautiful…"

"I love you," Lily whispered back. She laid her head on Bellatrix's breast, eyelashes fluttering against her skin.

"I love you too, my Lily." Bellatrix pulled the neckline of her dress down a little further, and Lily ran her mouth over the pale flesh. "In fact…" She gently pushed Lily's head off her breast, and fumbled in her pocket for something. "Lily, my Lily… oh, I'm no good at this sort of thing…"

Bellatrix pulled out a small box, wrapped in brown paper, and handed it to Lily.

"A present? Oh Bells, thank you. What's the occasion?" Lily kissed her girlfriend and carefully undid the wrapping paper.

Bellatrix said nothing, only coiled one of Lily's dark red locks around her finger and watched as the younger girl opened the package.

It was a small, silver box that looked fairly old to Lily. She admired it, then opened the lid.

Inside was a diamond ring.

"Bells?" Lily looked at Bellatrix, her eyebrows drawing together. "What is this?"

"Well, it's… I mean… do you like it?"

"It's beautiful, Bella, but…"

"Well, if you like it, then keep it," Bellatrix said. She was closing off fast, doing something Lily had seen many times before, any time someone got too close to Bellatrix's emotions. "It's a present. Try it on, see if it'll fit."

"Bellatrix," Lily said, startling the older girl with the use of her full name. "Is this an engagement ring? Were you going to ask me to marry you?"

Bellatrix's face flamed. "No! Of course not! You know I don't go in for that sort of thing!"

Lily slipped the ring over her finger. It was a perfect fit. She admired the effect for a few moments, then looked at Bellatrix.

The tender woman that only appeared when Bellatrix was safe in her room with Lily was gone, replaced with the usual Bellatrix. Cold and aloof. Virtually emotionless. Lily knew full well that Bellatrix had had every intention of proposing, she had just lost her nerve. It had happened before, many times, Bellatrix had been on the verge of asking Lily to marry her, and then pulled back. Bellatrix would consider admitting that she wanted to marry Lily a sign of weakness, and she so prided herself on her strength.

"Bells, give me your hand," Lily said.

"What?"

"Give me your hand," Lily repeated. She met Bellatrix's eyes, locked on them, as she carefully removed the ring from her finger, and slipped it on Bellatrix's.

"Bellatrix Black," she said, "will you marry me?"

Tears of happiness sprung to Bellatrix's eyes, and she flung her arms around Lily.

"I love you, my Lily," she said.

"Love you too, Bella," said Lily.


	2. Shag

Bellatrix had been married to Lily for nearly six years now, and if she was to be honest, it didn't suit her. Lily was a very sweet girl, but in her heart of hearts, Bellatrix craved excitement, and Lily was just not an exciting person.

"I'm going out," Bellatrix said. Lily was curled on the couch with wool and needles, working on a shawl.

"Where?" Lily asked.

"For coffee," Bellatrix told her. "With Tom Riddle."

Lily nodded. "How is Tom?"

"He's well," said Bellatrix shortly. If Lily kept this meaningless talk up, she was going to be late.

"You see him a lot."

Bellatrix sighed. "We just talk, Lily. Do you want to come with me, satisfy yourself there's nothing else going on?"

"Oh, no," said Lily. "I trust you, you know that, Bella. Tell him hello, from me. Maybe invite him for dinner this weekend."

"I will," Bellatrix said. "I'm going to be late. I'll see you later."

"Love you, Bella." Lily waved lightly as Bellatrix was heading out the door.

Bellatrix hesitated, then waved back. "I love you too, my Lily."

)O(

Bellatrix sat down opposite Tom Riddle. The coffee shop was bustling with activity, and she leaned close to him so that they could talk.

"I trust you're well, Bella?" he said.

"Not bad," she replied.

"How is Lily?"

"She's…" Bellatrix searched for the word. "Lily is… she's the same."

"Is she." Tom Riddle raised an eyebrow. "The same as what?"

"The same as ever."

"Oh, well then…" Tom raised his cup to his lips. "Being the same is better than changing for the worse, isn't it?"

"I suppose." Bellatrix stretched out her legs under the table, and her ankle brushed against his. "But it isn't as good as things changing for the better."

His lips twitched in a sort of slight smile. "And pray tell, Bellatrix, what would make things change for the better?"

"That's a very personal question." Bellatrix glanced down and then back up. "Oh, I don't know." She blew on her coffee and sipped it.

"You've never had problems answering personal questions before."

"I don't want to talk about it."

"Well then, talk about why you don't want to talk about it." This time it was Tom's foot that brushed Bellatrix's beneath the table. She bit her lip, tried to think about something asexual.

"You asked to meet me here," she said. "Was there something you wanted to talk about?"

"Yes, there was, actually." He put his coffee aside. "But I don't think this is the best place to do it. Somewhere more… quiet, perhaps?"

"If you like," said Bellatrix. She stood up, and so did Tom. "Where shall we go?"

"I have a flat above Borgin and Burke's."

"Oh." Bellatrix's heart skipped a beat. "Er… All right, then."

He held out his arm in mock-formality, and Bellatrix took it with an ironic tilt of the head.

Tom Riddle's flat was barely the size of Bellatrix and Lily's parlour. There was a small cupboard in a corner, a trunk at the foot of a small, hard bed. The whole place was beyond minimalist, but meticulously clean.

"Sit down," Tom said, gesturing at the bed. Bellatrix settled on the edge, and looked at him expectantly.

"What did you want to say?" she asked.

"I have a… request for you." Tom was pacing the flat, six paces across, six paces back, in front of Bellatrix.

"What sort of request?" she asked breathlessly. That sounded like a lead-in to something that a married woman shouldn't do.

He stopped in front of Bellatrix and looked down at her.

"As I'm sure you know," he said, "I head a substantial movement, for the purity of wizard blood."

Bellatrix looked at him questioningly. Well, she hadn't been expecting that. Why would he be talking to her about that? Tom said he liked to talk to her because it was refreshing to talk to such an intelligent woman, but he knew she didn't see eye-to-eye with him on blood purity. She was married to a Mudblood, after all.

"And the cause has need of your particular… skill set."

"I don't understand–"

"Let me be blunt, then. We need a woman who has the brains, and the stomach, to kill."

Bellatrix stared at him in horror. "To _kill_? Tom, I–"

"I know you're going to say that you couldn't kill anyone. But think clearly, Bellatrix. This person we need to have killed is not just anyone. She would see us all in Azkaban without a second thought. She would have me imprisoned for life, and you too for knowing me. She would even let the Dementors have Lily."

Bellatrix's eyes widened momentarily then narrowed. "I wouldn't let them."

"You wouldn't be able to stop them."

Bellatrix twisted her hands together. "I couldn't kill someone. Not in cold blood. If she attacked Lily, she'd be dead in a second, but…"

"Look," Tom said. He sat down next to her on the bed, put one of his hands over hers. "I know better than anyone this isn't an easy thing to do. I wouldn't ask you if I didn't think you could do it."

Bellatrix glanced at him, then looked away. He could be so charming when he wanted to be. She could almost kiss him. In fact, she would like little more than to kiss him…

"I'll make it worth your while," he said, leaning so close she could feel his breath on her ear.

"How?"

His hand left hers, and trailed to her stomach, then slowly up towards her breast.

"It's been a long time since you've been with a man, hasn't it?" he breathed. "You may love your Lily, but you crave a man, a man who will pin you to the bed and take you so hard you can scarcely stand afterwards. You want a man who you can battle with between the sheets, someone as strong and rough as you. Don't you?"

Bellatrix's heart was hammering against her ribcage. She had thought about Tom before – how could she not, he was a handsome man. And if she could have him, make love to him just once… if there was anything Bellatrix would kill someone for, it was that.

_I'm married. _ _I couldn't…_

"Lily–"

"Will never have to find out," Tom said. He lifted her thick black hair off her neck and kissed it. "Bellatrix, you are…"

Bellatrix moaned quietly. He was right, she did crave a man. Lily was sweet, and wonderful, and beautiful, but Tom was…

"Delicious," he whispered, and pushed her back, flat onto the bed.

)O(

Bellatrix lay, heaving and panting, lost in the aftermath. Tom was next to her, and he shone with sweat and lust, gasping for air.

"God, Tom," she managed. "That was…"

"It was indeed." He sat up, ran a hand through his hair, wiped his sweaty brow. "So, dear Bellatrix, am I to assume you are willing to help our cause, then?"

"On one condition." Bellatrix smirked at him.

"What would that be?"

"When I'm done with this person who needs to be killed," she said, sitting up as well, "we can do that again."

Tom smiled wickedly. "That sounds fair."


	3. Kill

Author's Notes: Warning: Sadistic, eye-related murder. If you don't like that, turn back now. Epilogue still to come.

)O(

_Marlene McKinnon_.

The name floated in Bellatrix's mind, a specter haunting her.

_How could I have agreed to kill someone? And for such a low price, too_…

"You all right, Bella?"

Bellatrix startled. Lily was looking at her, with an expression of honest concern on her face.

"I'm…"

_Marlene would see Lily handed over to the Dementors. Tom in Azkaban. Me too, just for knowing him. Poor Lily, with the Dementors…_

"I'm fine," Bellatrix lied.

"You'd tell me if something was wrong, wouldn't you?" Lily asked. She edged closer to her wife on the couch, touched Bellatrix's shoulder.

"Of course I would," Bellatrix lied again. "But nothing's wrong." Three lies. "Everything's fine." Four lies.

"You look sick," said Lily. She pressed her cool, soft hand to Bellatrix's cheek. "Maybe you're coming down with something."

"You ought to be a mother," Bellatrix said dryly.

"I'm happy being just a wife," Lily reminded her. She wrapped her arms around Bellatrix, and rested her head on her shoulder.

"Lily?"

"Yes, Bella?"

Bellatrix hesitated, then asked, "What do you know about Marlene McKinnon?"

"Marlene?" Lily raised her head and looked at Bellatrix, confused. "I went to school with her. Why?"

"Tom mentioned her," Bellatrix said. It was true, although not the whole story, of course.

Lily shrugged nonchalantly. "She was in most of my classes. My year, Gryffindor also. Very smart. Nice enough."

"You were friends?"

"Not really," said Lily. "But we weren't _not_ friends, you know?"

Bellatrix made a non-committal little noise. She hadn't really had not-not friends at school. She had had a small handful of friends, and dozens of rivals and enemies, but little in between.

"Your cousin knew her better than I did," Lily said. "Sirius. And those others too, what do they call themselves? The Order of something or other…"

"The Phoenix?"

"Yes, that's it."

"Why are we talking about this?" Lily asked, twisting her hands in Bellatrix's hair. "Marlene's nothing special."

"Not compared to you, I'm sure, my Lily," Bellatrix purred, pulling the other woman into her lap. Lily laughed, and kissed her wife.

Bellatrix kissed back, but her mind was on Marlene McKinnon, and how she could get her dead. And, if she was to be honest, she was also thinking of Tom…

)O(

Marlene McKinnon was coming out of her Ministry office when she ran into the dark woman.

"Can I help you?" she asked, rather distracted. _Let me see, if I go straight home, I'll have time to look over my papers before the meeting_…

"Are you Marlene McKinnon?" the woman asked.

"Yes."

"Bellatrix Black-Evans," she said, putting out her hand for Marlene to shake.

"Do I know you?"

"Not as such. I'm Lily Evans' wife. But I was told I should talk to you about…" she trailed off and glanced to either side, as though worried someone would see them talking. Then she dropped her voice to a whisper. "The Order of the Phoenix."

Marlene's heart skipped a beat. "Pardon?"

"The Order of the Phoenix," Bellatrix repeated. "You are a member, aren't you?"

"I don't know what you're–"

"Because," Bellatrix continued, voice dropping to a low whisper, "I could give the Order information about Tom Marvolo Riddle that could help you greatly…"

"I can't help you," Marlene said shortly. "I'm sorry, I might be able to send someone…"

"You don't understand," said Bellatrix urgently. "I _have_ to talk to you. To _you_. Only you."

Marlene glanced over her shoulder. "We shouldn't be here. There are spies everywhere."

"Where should we go, then?" whispered Bellatrix.

Marlene hesitated. The Order of the Phoenix was an illegal organization, and she shouldn't go around telling people that she was part of it. But clearly this Bellatrix already knew she was part of it. And if she was married to Lily…

_She's friends with Tom Riddle… if she really is willing to help us, then she could tell us a lot…_

"Come on," said Marlene. She indicated that Bellatrix should follow her, then walked nonchalantly towards the exit.

"Where are we going?"

Marlene said nothing, only led Bellatrix out of the Ministry building, into the streets of London.

The two women hurried through the roads adjacent to the Ministry, then Marlene led the way into an Underground station.

"What–" Bellatrix began, but Marlene just shook her head, and pulled Bellatrix through one of the busy terminals, down a moving staircase (Bellatrix watched the staircase warily, holding her skirts out of the way of all the moving parts), and into the bowels of the station.

The crowds thinned as they went down the staircases, until they were nearly alone. At the very bottom level, where there were only a few rather tired-looking muggles, Marlene led Bellatrix to the edge of one of the platforms. She glanced around, making sure there was no one to see them, then lowered herself onto the tracks and beckoned Bellatrix to follow, which she did.

"Why are we here?" Bellatrix asked, putting her hand on the handle of her wand.

"No one to find us," Marlene said.

"You're sure no one will find us here?"

"Positive."

In the dark, Marlene couldn't see the smirk twisting Bellatrix's face.

"Now, tell me what you know about Riddle."

"Before I do," said Bellatrix, "There's something I think you should know."

"What?"

"Well, technically speaking, this makes me a double agent…"

"_Get to your point._"

Bellatrix drew her wand and pointed it at Marlene. "You should never trust a double agent."

Marlene's hand flew to her wand, but Bellatrix had her disarmed in a second.

"Now, you see, I was told you were intelligent," Bellatrix said conversationally. "Only, I don't think you can be very, because no one intelligent would take a complete stranger who just happens to know that they are a member of an illegal organization into an empty…" she looked around scornfully, "train station."

"What the Hell kind of game do you think you're playing?" asked Marlene in a low voice. "What would Lily say if–"

"Lily! Lily! Lily! _Crucio_!" Bellatrix slashed her wand in Marlene's direction, and the woman was thrown back across the track.

"Don't you dare talk to me about Lily! Lily this and Lily that, everything's about Lily! I don't give a damn about Lily!"

Marlene stifled a sob of pain, tried to sit up, but Bellatrix was on her in an instant. She clutched the front of her robes, held her still.

"You're quite pretty, you know, Marlene," Bellatrix murmured. "Eyes all big and afraid, shaking, quivering…" She ran the tip of her tongue around her lips. "Such a pity I have to kill you."

"Crazy…" Marlene managed. "You're… crazy…"

"Perhaps I should have a little fun with you first," Bellatrix continued. "We could have such a lovely time… you could die happy…"

Marlene spat.

"No?" Bellatrix used her wand to trace a delicate pattern over the curve of Marlene's breast. "Are you sure?"

"Get away from me, you bitch," hissed Marlene.

Bellatrix shrugged, and aimed her wand at Marlene. "Well, if that's the way you want it."

She moved her wand around, trying to decide where to attack. _Heart? No, too protected. Throat? No, too unoriginal. I'll go straight for the eyes…_

Bellatrix held Marlene steady, aimed her wand dead at her left eye.

"Ever wondered what it's like to be blind?" she purred, and shoved her wand into Marlene's eye socket.

Marlene screamed, tried to shut her eyes, and too late. Bellatrix moaned softly, enjoying the sight of the woman writhing, with Bellatrix's wand driven into her head. "And here I thought I wouldn't be able to kill someone..."

The tracks trembled, a train was approaching.

Bellatrix pulled her wand out, very slowly, laughing and Marlene's shrieks of anguish. She wiped it on Marlene's robes, then stood up.

" Good bye, Marlene McKinnon," she purred, and disapparated.

The last thing that Marlene saw, near-blind and in excruciating pain, was the single eye of the train's light, bearing down on her.


	4. Epilogue

Marlene McKinnon's funeral was possibly the most difficult day of Bellatrix's life.

Lily had been on the verge of tears since the article on Marlene's death had been in the paper.

"I just can't believe someone would do this," she kept saying. "Who would do something like this?"

Every time Lily asked that, Bellatrix would just shake her head and say she didn't know.

She went to the funeral, not because Lily wanted to go and said she needed Bellatrix there to make sure she didn't fall apart, but because she wanted to convince herself that Marlene McKinnon really was dead. She wanted to see the coffin lowered into the ground and the earth heaped on it, so that she knew beyond the shadow of any doubt that she was gone.

Bellatrix and Lily sat at the back of the church, Bellatrix craning her neck to keep an eye on the coffin every minute, and Lily sobbing into her wife's shoulder. Bellatrix tried to summon tears, but her eyes were stubbornly dry.

Bellatrix was shocked, when the service was over, to see Tom Riddle going over to the McKinnons to offer condolences. Leaving Lily momentarily, she dragged him aside.

"What do you think you're playing at?" she hissed. "Why are you here?"

"I make a practice of coming to funerals. It is rarely unappreciated," he said, raising his eyebrows at her vehemence.

"You caused her death!" Bellatrix whispered, glancing around to make sure no one was watching them.

"I think you'll find that it was you who caused her death, Bella," Tom said, the amusement obvious in his voice.

"At your request!"

"Quite. Has it been bothering you, Bellatrix?"

"Of course!" Bellatrix said, more loudly than she had intended. Several people glanced their way and she lowered her voice to a whisper again. "I _killed_ her, of course it's bothering me!"

"But it isn't bothering you that she's dead," said Tom, mildly. "What's bothering you is that you enjoyed it."

"I didn't enjoy it!"

"I know you did," he told her, putting a hand on her shoulder and turning her slightly so that she was shielded from the prying eyes of the funeral goers. "You don't have to lie to me, Bellatrix. If anyone understands what a beautiful thing it is to inflict death, it's me."

Bellatrix's heart was fluttering erratically. The memory of Marlene's screaming, her incredible pain, the near-euphoric satisfaction that Bellatrix had felt when she drove her wand through the woman's eye socket, and of Tom, of them together in his flat above Borgin and Burkes, all mixed together in her mind, until she couldn't tell which had given her pleasure and which pain.

"You're crying, Bella," he commented. Bellatrix raised a hand to her cheek, and was surprised to find it wet.

"It will be easier next time, my Bella," he told her. "The first one is always the hardest."

"Next time?"

"Oh yes, my Bella, there will most certainly be a next time. Even if didn't have other people who needed to be killed, I know you would find some. Murder isn't something you can commit just once."

Bellatrix bit her lips.

"There's no point in saying otherwise, is there?" she asked.

"None whatsoever. I know you would kill anyone to help me, wouldn't you?"

She nodded. There was no reason to lie, he knew exactly what she thought.

"Even someone you never thought you could kill," he said. "You could do anything, for me."

Tom looked over his shoulder, then, satisfied that no one important was watching, drew Bellatrix into an embrace. She rested her head on his shoulder, and he whispered into her ear,

"I already have your next… assignment."

"Who?"

"Bella, we need to go," Lily said, coming up to them and touching Bellatrix's shoulder.

"Well, speak of the devil," he whispered, then broke away from her, tilted his head to Lily, and strolled off.

_Speak of the devil…_

Bellatrix looked from Tom's retreating back to her wife, standing at her side with an expression of concern.

Lily?

)O(

_Fin_


End file.
